<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">    
    <title>20-21</title>
    <link rel="stylesheet" href="css/css.css">
</head>
<body>
    <div id="box">
        <div id="box-fade">
            <button id="fade-btn">淡出</button>
            <div id="fade-obj"></div>
        </div>
        <div id="pic-box"></div>
    </div>  
</body>
<script src="js/js.js"></script>
</html>
